In general, electrical circuit breakers are used to protect lives and personal property, and as such require that the design is safe and reliable. These circuit breakers are composed of various components and among those components are springs used for various compression and extension type applications.
For safe operation of these components, it is often crucial that the springs stay at an exact position at the component and, hence, reliably apply spring power at a desired spot. In case the spring changes its position or even completely drops off the component, malfunction of the component can be the result. Especially for security relevant components, such malfunction must he avoided. However, many spring designs do not utilize a device for keeping the springs in place, especially when circuit breakers are manufactured. In some cases, these springs have functionally failed when these springs have fallen from their contact areas. The dislodging of these springs has caused catastrophic failures.
To overcome the problem of dislodging springs, securing compression springs at both ends has been done at an added premium cost to the product. These added costs include but are not limited to the addition of extra parts, which would add to tooling costs, an increase in tooling costs as well as an increase in BOM and inventory. Moreover such designs added to the assembly costs of a product.
If the second end of the spring cannot be secured, the first end of the spring can be bonded or glued inside a guided seat. However, the trouble with such an alternative is the reliability of the bonding joint, which highly depends on the degreasing and cleaning mold release agent use during manufacture and assembly as well as the oxide on stored parts. In addition, the reliability and added costs of the product are affected by the selection of the proper bonder or primer, the added cost of a curing time for the epoxy, the application of the glue which can at times unreliably bond more than the 1st loop, and glue the 2nd or 3rd loop so as to impede the proper function of the spring—since it in effect reduces the number of active coils. All of the above would also apply to an insertion plastic molding process, where one end of the spring would be secured by being over-molded embedded with plastic in the mold.